Republicans joined Democrats on Wednesday in pressuring the Trump administration to surrender records of former national security adviser Michael Flynn's payments and contacts with foreign officials during the past three years.

In a sign of deepening interest among congressional investigators, leaders of the House Oversight and Government Reform Committee asked for materials on Flynn's communications and payments from Russian, Turkish and other foreign sources since Flynn retired as head of the Defense Intelligence Agency in August 2014.

The request came as a Flynn spokesman said the retired general filled out all of his security clearance paperwork, but did not sign a mandatory ethics pledge during his time as national security adviser.

Also sought by the committee chairman, Republican Rep. Jason Chaffetz of Utah, and the top Democrat, Rep. Elijah Cummings of Maryland, is any available material on Flynn's security clearance, which would have been required to allow him access to highly classified government documents and information. The two congressmen made the requests in letters to White House chief of staff Reince Priebus, FBI Director James Comey, Defense Secretary Jim Mattis and National Intelligence Director Dan Coats.

President Donald Trump fired Flynn last month for misleading Vice President Mike Pence and other top administration officials about Flynn's postelection conversations with Russia's ambassador to the United States.

Bipartisan front

The committee's move is significant because of the bipartisan front and the effort to gain broad information about Flynn's foreign-related work and communications for an extended period before Trump appointed him in January.

Cummings said the goal is to learn whether Flynn “was untruthful on his security clearance forms, his vetting materials, and in other documents - conduct that could carry a criminal penalty - and we want to know what the White House knew when they hired him as national security adviser.”

The committee also wants to determine whether Flynn violated the constitutional prohibition against foreign payments to former military officials who could be called back into service.

The FBI has interviewed Flynn about his Russia contacts as part of its inquiry into meetings, phone calls and electronic contacts last year between Trump campaign aides and Russian officials and others representing Russian interests.

The House request comes a week after the committee released documents showing Flynn accepted more than $33,750 from the Russian government-backed RT network for a trip to Moscow in 2015, before he joined the Trump campaign. U.S. intelligence agencies have described that network a propaganda arm of the Russian government.

FILE - Russian President Vladimir Putin (R) sits next to retired U.S. Army Lieutenant General Michael Flynn (L) as they attend an event marking the 10th anniversary of Russia's RT television news channel in Moscow, Russia, Dec.10, 2015.

Cummings and Chaffetz cited Flynn's payments from RT in their letters as they sought information about the retired Army lieutenant general's responses to security clearance questions, as well as “any other security clearance applications, certifications, or requests for periodic reinvestigation.”

The letters also ask for any “investigative and adjudicative” files concerning Flynn's clearance. The lawmakers want to see “documents referring or relating to Lt. Gen. Flynn's contact with foreign nationals,” including any direct or indirect contacts between Flynn “and foreign government officials, representatives, affiliates, or agents.”

Price Floyd, a spokesman for Flynn, said Flynn met the disclosure requirement for national security adviser. “Everything that was supposed to be included was included,” Floyd said.

He said Flynn last came up for a security clearance review in January 2016, and disclosed his trip to Russia to attend an RT event. Flynn also took a polygraph - required of someone with his level of security clearance - and passed, Floyd said.

Trump signed an executive order on January 28 prohibiting political appointees from lobbying the government in any way for five years after serving in his administration. That same order instituted a lifetime ban on outgoing officials representing foreign governments.

Ethics pledge

Floyd said Flynn “didn't have the opportunity to sign” the ethics pledge, “but he is going to abide by the pledge.” Floyd said Flynn has not engaged in any lobbying work since leaving the White House that would have violated the pledge.

White House spokeswoman Stephanie Grisham said Wednesday that “all applicable employees have signed the ethics pledge.” She did not answer questions about why Flynn had not. The White House did not immediately respond to a request to review those documents. The Daily Beast first reported on Flynn's failure to sign the pledge.

In addition to his RT contacts, Flynn filed paperwork this month with the Justice Department as a foreign agent whose lobbying work between August and November last year may have aided the government of Turkey. Flynn's consulting firm, Flynn Intel Group, registered as a lobbyist last year for Inovo BV, a Dutch-based company owned by a Turkish businessman.

After Flynn's lawyers consulted Trump's legal team during the transition and after Flynn's appointment, he and his firm re-filed as foreign agents, a distinction that requires much more detailed documentation with the Justice Department.

The owner of Inovo BV, Ekim Alptekin, told The Associated Press that Flynn and his firm did so due to pressure from Justice Department officials.

The committee letters also ask for Flynn's “receipt of funds from any foreign source,” as well as documentation of any efforts by Flynn to seek government approval for payments from foreign sources.

The committee also asked the agencies for new documents relating to Flynn's work for Leading Authorities Inc., which handles Flynn's speaking requests.

Last week, the committee posted material from the firm, including copies of checks Flynn received from RT and two other Russian companies, as well as emails between Leading Authorities, RT officials, and Flynn and his adult son, Michael Flynn Jr., who accompanied his father on the Moscow trip.